How to suppress conducted interference on data center switch ports?

Conducted interference from data center switch ports mainly originates from common-mode current flowing back to the power supply via the network cable. The 150kHz-30MHz frequency band limits are based on EN55032 Class B. Suppression measures include: connecting a 1000pF/2kV high-voltage capacitor in parallel with ground at the center tap of the network port transformer to shorten the common-mode return path; using a PBZ1608A-102Z0T ferrite bead (1000Ω@100MHz) in series with the signal line to increase common-mode impedance; adding LC filtering (1μH+10μF) to the PHY chip power pins; and ensuring a low-impedance connection between the RJ45 metal casing and the chassis ground on the PCB (grounding impedance <10mΩ). Actual measurements show that these measures reduce conducted interference from the network port by 15-22dB in the 1MHz-10MHz frequency band, exceeding the Class B limit margin by >4dB.